Thermoplastic polyurethane (TPU) having high impact-resistant strength has been so far used as a base material for a protection film or the like. In particular, in Europe and the United States, a film for protecting a body of a vehicle from stone bouncing, a scratch or the like has been widely prevailing under the name of a paint protection film (PPF). For example, Scotchgard Paint Protection Film made by 3M Company is available.
As a protection film using thermoplastic polyurethane, Patent literature No. 1 discloses a multilayer film used for protecting a surface, particularly, a film used for protecting a surface (for example, a coated surface) of a vehicle (such as an automobile, an aircraft and a ship), and more specifically, a multilayer protection film prepared by processing a back by a pressure-sensitive adhesive and having a polyurethane layer in an uppermost part of a thermoplastic polyurethane layer (paragraph 0001). A painted surface of a body part of the vehicle is protected by the multilayer protection film
An object of the protection films is typically to protect the surface of an article from an external element to prevent the article from being scratched. In recent years, requirements have been further expressed on the protection film that protects the article, and additionally has self-restoring properties of smoothening a scratch of the protection film itself even when the protection film is scratched, and stain-proof properties for preventing attachment of stains.